A cursor in SQL is a database object stored in temp memory and used to work with datasets. You can use cursors to manipulate data in a database, one row at a time. A cursor uses a SQL SELECT statement to fetch a rowset from a database and then can read and manipulate one row at...
deallocate [ Global ] cursor_name | cursor_variable_name --释放游标 deallocate orderNum_03_cursor 使用实例: USE Test_DB; DECLARE @jid CHAR(5) DECLARE @pic NVARCHAR(64) DECLARE My_Cursor CURSOR --定义游标 FOR (SELECT jid FROM journal WHERE isall in(1,2)) --查出需要的集合放到游标中 OP...
SQL is a set-based language, meaning operations are completed on all or rows of the result. However, there are times, when you want to do operation on a row by row basis. This is where cursors come in to play. What is a Database Cursor?
CURSOR: cursor is a handle or pointer to the context area. Related Answered Questions PL/SQL block cursor Cursor and bulk collect Difference between impicit index and explicit cursor What is the use parameterized cursor in PL/SQL ? Oracle cursors in PL/SQL ...
84. What is TRUE about %ROWCOUNT in PL/SQL Cursor? A SELECT INTO statement or DML statements like INSERT, DELETE, AND UPDATE do not result in any rows being affected. Results are returned for DML statements such as inserting, deleting, and updating records, or for those returned by a SEL...
Let’s dive in!!! What Is PL/SQL PL/SQL is a fusion of SQL with procedural traits of programming languages. It was launched by Oracle to upgrade the features of SQL. PL SQL is considered as one of the important languages inside the Oracle database. It is primarily an extension of SQL...
Nested tables defined in PL/SQL have many more operations than previously. You can compare nested tables for equality, test whether an element is a member of a nested table, test whether one nested table is a subset of another, perform set operations such as union and intersection, and much...
Rowset functions Return an object that can be used like table references in a SQL statement. Scalar functions Operate on a single value and then return a single value. Scalar functions can be used wherever an expression is valid. Categories of scalar functions Expand table Function categoryDescr...
Step 6: Executing SQL Queries Upon securing a connection, SQL commands can be executed with ease. For instance, here’s how to retrieve all entries from ‘example_table’. cursor = conn.cursor()cursor.execute("SELECT * FROM example_table")for entry in cursor: print(entry) Step 7: Safely...
in lieu of an explicit cursor, when PL/SQL encounters a SELECT statement that returns just one row or when data manipulation language statements, like DELETE, INSERT or UPDATE, are encountered. Explicit cursors grant users better control over the context area and should be used with a SELECT ...